Burnley have welcomed a positive update on Martin Paterson's hamstring problem, but are less optimistic regarding Junior Stanislas.
Both men have undergone scans, and it is believed that Paterson could be sidelined for less than a month.
Clarets winger Stanislas, however, faces up to eight weeks out with a similar injury.
Turf Moor boss Eddie Howe discovered the results of the scans on Wednesday after the pair suffered setbacks in the 2-0 Championship victory at Middlesbrough last weekend.
In a statement released by the club, Howe insisted: "It is particularly encouraging news for Martin.
"It was always a positive that the injury was not thigh-related and hopefully he could only be out for four weeks.
"Junior is expected to be a little longer than that, but we know both players are in good hands with our physio team and we look forward to welcoming them back sooner, rather than later."